group() public method
Performs aggregation using MongoDB "group" command.
public array group ( $collectionName, $keys, $initial, $reduce, $options = [] )$collectionName string
Collection name. $keys mixed
Fields to group by. If an array or non-code object is passed, it will be the key used to group results. If instance of \MongoDB\BSON\Javascript passed, it will be treated as a function that returns the key to group by. $initial array
Initial value of the aggregation counter object.